JP2005260778A - Monitoring camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a sharper image by changing a magnification power of an optical system while using imaging devices of the same resolution for a wide image pickup system and a moving object image pickup system. <P>SOLUTION: The monitoring camera is provided with: a CCD camera 1 for photographing a wide image A of an observation spot; and a CCD camera 2 for photographing a moving object captured in the wide image in a high magnification image B. At least the CCD camera 2 is supported by a double-axis rotary stage 3 so as to be freely movable in a two-dimensional manner, a motion and a position of the moving object M present in the wide image on a screen are detected based on a video output from the CCD camera 1, and the double-axis rotary stage is controlled to trace the detected mobile object M by turning the CCD camera 2 thereto. Both or either one of video outputs from the CCD camera 1 and the CCD camera 2 can then be outputted selectively by switching. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a surveillance camera that captures an image of an entire observation range with a wide-area imaging system with a low magnification, and images a moving body that has entered the imaged observation range with a high magnification.

  As a conventional technique for capturing an entire image of a place to be observed and a magnified image of a moving body such as a person existing at the place, Cited Document 1 has a plurality of image sensors (CCDs) installed, and each image sensor from an objective lens. It is disclosed that a half mirror is arranged in the optical path up to and the subject image divided by the half mirror is picked up at different magnifications by each image sensor through high and low magnification lenses and output as an electrical signal. .

  However, there is no mechanism for detecting the movement of a person and tracking a high-magnification imaging system in accordance with the movement. For this reason, there is a drawback in that a person cannot be imaged at a high magnification over the entire observation range and monitored with a clear image.

  In addition, moving the surveillance camera toward the observation target has been proposed in Reference Document 2, but this method changes the zoom magnification relative to a predetermined camera, and is imaged with a low magnification camera. The movement of the moving body existing in the wide area image detected is not detected, and the high-magnification camera is thereby tracked to take an image.

Japanese Patent Laid-Open No. 9-186917 JP 2001-285842 A

Until now, development of new elements and image transfer means has been necessary to monitor a wide area with high resolution. Conventional surveillance cameras are based on the television signal standard and cannot capture a person's face clearly when shooting a wide range. In addition, when taking a picture at a magnification that clearly shows a person's face, there is a problem that only a very limited range can be taken and it is not suitable for monitoring.
An object of the present invention is to provide a surveillance camera that can obtain a clearer image by changing the magnification of an optical system by using an imaging device having the same resolution for a wide-area imaging system and a moving body imaging system.

According to a first aspect of the present invention, there is provided a surveillance camera comprising: a wide-area image capturing unit that captures a wide-area image of an observation place; A two-axis rotary stage that is movably supported in three dimensions and directs the optical axis of the optical system of the high-magnification image pickup means to the moving body, and a moving body that exists in the wide-area image based on the video signal output from the wide-area image pickup means And a control means for controlling the biaxial rotary stage so that the high-magnification image pickup means is made to track the detected mobile body and the moving body taken by at least the high-magnification image pickup means. Video output means for outputting a high-magnification image.
According to the first aspect of the present invention, since two video cameras are used as the imaging means, the existing equipment can be used for the cable, the recording device, etc., and a wide range can be monitored with high resolution. .

A second aspect of the invention is characterized in that, in the first aspect of the invention, the wide-area image capturing means is fixed.
According to the second aspect of the present invention, the image pickup means for wide area is fixed, and the area to be monitored is limited, thereby making it easy to control the image pickup means for tracking.

A third aspect of the invention is characterized in that, in the first or second aspect of the invention, the video taken by the wide area image pickup means is selectively output.
According to the invention of claim 3, two sets of the image transfer cable, the monitor and the recording device are required for monitoring and recording the wide area image and the high resolution image, but the cable is obtained by switching and outputting the two images. The monitor and the recording device can be realized in one set, and can be used even when there is only one image signal cable and the recording device, such as when replacing a conventional surveillance camera system.

A fourth aspect of the present invention is characterized in that, in any one of the first to third aspects, the moving body is a person.
According to the invention of claim 4, it is determined whether or not the person is a person by using a human face determination method or the like from the image of the area where the moving body is detected, and if the person is a person, the high-magnification image capturing unit tracks the person. To. This eliminates the tracking of animals such as dogs and cats and dust blown by the wind, thereby improving the observation accuracy.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the image processing apparatus includes a storage unit that records the video output.

The surveillance camera according to the invention of claim 6 is a wide-area image capturing means for capturing a wide-area image of an observation place, and a high-power image capturing means for capturing a predetermined specific area within the wide-area image captured by the wide-area image capturing means at a high magnification. And a wide-area image pickup means and a high-magnification image pickup means are two-dimensionally movably supported, and the optical axes of the optical systems of the wide-area image pickup means and the high-magnification image pickup means are simultaneously two-dimensionally directed toward the moving body. The movement and position of the moving body existing in the wide area image on the screen are detected based on the two-axis rotating stage to be output and the video signal output from the wide area image capturing means, and the detected moving body is detected in the specific area of the wide area image. The wide-area image pickup means and the high-magnification image pickup means so as to enter, and then control means for controlling the two-axis rotation stage so as to be tracked by the moving body; Means, characterized in that it comprises a video output means for outputting the high-magnification image of the moving object taken by.
According to the invention of claim 6, by making the wide-area image capturing means movable, it is possible to realize a wider range of monitoring than the surveillance camera of claim 1.

A seventh aspect of the invention is characterized in that, in the sixth aspect of the invention, the control means controls the biaxial rotary stage so that the moving body is positioned at the center of the wide area image.
According to the invention of claim 7, the moving body is controlled to be positioned at the center of the wide area image imaging means by aligning the center of the imaging area of the high magnification image imaging means with the center of the imaging area of the wide area image imaging means. Thus, the moving body is located in the area of the high magnification image capturing means. As a result, the moving body can always be monitored by the high magnification image capturing means.

The invention of claim 8 is characterized in that, in the description of claim 6 or 7, the moving body is a person.
According to the invention of claim 8, the same effect as that of the invention of claim 4 can be obtained.

  A ninth aspect of the invention is characterized in that in any of the sixth to eighth aspects, a storage means for recording the video output is provided.

The surveillance camera according to claim 1 is suitable for monitoring a limited area such as a room, an entrance / exit, a passageway, a parking lot, etc., in order to photograph only a moving object detected by a wide area camera with a high resolution camera. It is possible to shoot a person with high resolution while monitoring a wide range.
The surveillance camera according to claim 6 is suitable for monitoring a wide area where there is no moving body such as a person at night in a wide range such as a conference room, an arena, a park, a playground, and a factory. When there is no moving object, the whole is scanned slowly, but when a moving object is detected, the moving object can be tracked to enable photographing with a high resolution camera.

  The present invention has realized that the use of a high-resolution element is disadvantageous in terms of the price and speed of the element, by using an inexpensive element having an optical system with different magnification and not so high in resolution.

  FIG. 1 is a screen for explaining the first embodiment of the surveillance camera according to the present invention, and shows the imaging range of the fixed camera and the tracking of the tracking camera. FIG. 2 is a conceptual diagram of the surveillance camera, and FIG. 3 is a control block diagram.

  In the first embodiment, as shown in FIG. 1, the entire observation range A is imaged by a fixed camera (hereinafter referred to as CCD camera 1) composed of a solid-state imaging device (CCD), and the movement that has entered this observation range is performed. The body M is detected, the coordinates of the left and right (X) direction and the vertical (Y) direction of the moving body M are obtained from the observation origin of the predetermined observation range, and the tracking constituted by the solid-state imaging device (CCD) is obtained at these coordinates. Control is performed so that the camera (hereinafter referred to as CCD camera 2) is directed, the moving body is tracked, and a narrow range B including the moving body is imaged by the CCD camera 2.

  This embodiment uses a low-power CCD camera 1 that captures a wide-area image at an observation location as a wide-area image capturing unit, and a high-power CCD camera 2 as a high-power image capturing unit. An image is picked up by a high-power CCD camera 2 while following a moving object captured in the image, for example, a person.

  In FIG. 2, the surveillance camera is composed of a CCD camera 1, a CCD camera 2, a biaxial rotation stage 3, and a control unit 4. The CCD camera 1 converts incident light of a low-magnification optical system into a color or monochrome video signal 1 using a CCD, and outputs it. The CCD camera 2 is supported by a biaxial rotating stage 3 so that the optical axis is directed in the left-right (X) direction and the up-down (Y) direction, and incident light of a high-magnification optical system is color or monochrome video signal by the CCD. Convert to 2 and output.

  The two-axis rotary stage 3 employs a known tracking mechanism, and the main elements include an X-axis movable mechanism that is operated by the motor (1) and a Y-axis movable mechanism that is operated by the motor (2), and these are combined. Thus, the optical axis of the CCD camera 2 can be directed to an arbitrary direction of the XY coordinates.

  The control unit 4 incorporates a program for realizing the processing shown in FIG. 4, detects the presence of the person M in the entire image A in the observation range based on the video signal 1 output from the CCD camera 1, and When M is detected, the coordinates of the person M are obtained, and on the basis of the position information on the screen, the biaxial control circuit controls the rotation of the motor 1 and the motor 2 of the biaxial rotary stage 3 to control the CCD camera 2. A person M is tracked according to the movement of the person M. The CCD camera 2 outputs a video signal 2 of the person M.

The motion detection algorithm will be described with reference to the drawings. Image data at a certain time is stored (FIG. 5). This processing (hereinafter referred to as the previous image) is usually a video signal, and usually captures a frame image in which odd and even fields are combined. In this case, the frame rate is 30 frames per second. Image data at the next time point is captured (FIG. 6). Subtraction is performed between each pixel of the previous image and the current image (hereinafter referred to as the current image) (FIG. 7). As a specific example, if the brightness of the previous image is I (Xm, Yn) and the brightness of the current image is i (Xm, Yn),
I (Xm, Yn) -i (Xm, Yn)
Get.

  A portion having a large change is detected in the difference image (FIG. 8). Here, assuming that the difference is larger than the threshold value, the center of the area having the change is obtained (FIG. 9). There are two methods for obtaining the center, such as a method for calculating the center of gravity of an area with movement, and a method for obtaining the horizontal and vertical positions of the area with movement as an approximation. Thus, the system controls to align the direction of the high-magnification optical system (CCD camera 2) with the central coordinate direction of the area where there is a change obtained by the motion detection algorithm.

  FIG. 10 is a screen for explaining a second embodiment of the surveillance camera according to the present invention, showing the imaging ranges of the CCD camera 1 and the CCD camera 2 and the state of tracking by both cameras. FIG. 11 is a conceptual diagram of the surveillance camera, and FIG. 12 is a control block diagram.

  In the second embodiment, a tracking camera of a double optical system combining a wide area and a high magnification is used. Specifically, the CCD camera 1 images the entire observation area A (wide area) at a low magnification, and the CCD camera 2 Is configured to image the central portion C of the observation range A at a high magnification. The tracking control of the CCD camera 1 and the CCD camera 2 moves so that the moving body that has entered the observation range A, for example, the person M is positioned at the center of the observation range A, and is directed according to the movement of the person M.

  The biaxial rotating stage 3 has the same function as that of the first embodiment, and main elements include an X axis movable mechanism operated by the motor (1) and a Y axis movable mechanism operated by the motor (2). Are combined so that the CCD camera 1 and the CCD camera 2 are positioned at the center of the person M who has entered the observation range.

  The control unit 4 incorporates a program for realizing the processing shown in FIG. 13, detects the presence of the person M in the entire image A in the observation range based on the video signal 1 output from the CCD camera 1, and When M is detected, the coordinates of the person M are obtained, and the difference between the coordinates and the center coordinates on the screen is made zero, that is, the two-axis control circuit rotates two axes so that the person M is always located at the center. The rotation control of the motor 1 and the motor 2 of the stage 3 is performed so that the CCD camera 1 and the CCD camera 2 are simultaneously tracked according to the movement of the person M. In this situation, the CCD camera 1 outputs the video signal 1 and the CCD camera 2 outputs the video signal 2.

The motion detection algorithm will be described with reference to the drawings.
The coordinates of the moving body are detected from the image of the CCD camera 1 (FIG. 14). Detection of the moving body and its coordinates is the same as in FIGS. The camera is moved so that the moving body is at the center of the screen (FIG. 15). Thus, in the case of a dual optical system tracking system, the moving body is always at the center of the screen.

  In the first and second embodiments, the video signal 1 of the CCD camera 1 and the video signal 2 of the CCD camera 2 are both output in parallel, or usually the video signal 1 is output. Switch to output. As this condition, for example, it is configured to be switched when there is motion detection.

FIG. 6 is a diagram showing a screen for explaining a first embodiment of the surveillance camera according to the present invention. FIG. 3 is a schematic diagram of a surveillance camera for explaining a first embodiment. FIG. 3 is a control block diagram of the first embodiment. FIG. 6 is a diagram showing a processing flow of the first embodiment. It is explanatory drawing which memorize | stores this time image in a motion detection algorithm. It is explanatory drawing of acquisition of the last image. It is explanatory drawing which calculates | requires the difference image of the last image and this image. It is explanatory drawing which detects the part with a big change in a difference image. It is explanatory drawing which calculates | requires the center of an area with a change. It is a figure which shows the screen for demonstrating a 2nd Example. It is a schematic diagram of a surveillance camera. It is a control block diagram. It is a figure which shows the processing flow of a 2nd Example. It is explanatory drawing which detects the coordinate of the moving body in a motion detection algorithm. It is explanatory drawing which moves a camera so that a mobile body may become the center of a screen.

Explanation of symbols

1 CCD camera 1 (wide area image pickup means)
2 CCD camera 2 (high magnification image capturing means)
3 2-axis rotary stage 4 Control unit A Wide-area image B High-magnification image M Moving object

Claims (9)

A wide area image capturing means for capturing a wide area image of the observation place;
A high-magnification image capturing means for capturing a moving object captured in the wide-area image at a high magnification;
A two-axis rotary stage that supports the high-magnification image pickup means in a two-dimensional manner, and directs the optical axis of the optical system of the high-magnification image pickup means to the movable body;
Based on the video signal output from the wide area image pickup means, the movement and position of the moving body existing in the wide area image on the screen are detected, and the detected high speed image pickup means is made to track the moving body. Control means for controlling the two-axis rotary stage;
Video output means for outputting a high-magnification image of the moving body taken by at least the high-magnification image capturing means;
A surveillance camera characterized by comprising:   2. The surveillance camera according to claim 1, wherein the wide-area image capturing means is fixed.   3. The surveillance camera according to claim 1 or 2, wherein the video taken by the wide-area image capturing means is selectively output.   The surveillance camera according to claim 1, wherein the moving body is a person.   5. The surveillance camera according to claim 1, further comprising storage means for recording the video output. A wide area image capturing means for capturing a wide area image of the observation place;
A high-magnification image imaging means for taking a predetermined area in a wide-area image taken by the wide-area image imaging means at a high magnification;
The wide area image pickup means and the high magnification image pickup means are movably supported in a two-dimensional manner, and the optical axes of the optical systems of the wide area image pickup means and the high magnification image pickup means are simultaneously two-dimensionally operated toward the moving body. A two-axis rotary stage;
Based on the video signal output from the wide area image capturing means, the movement and position of the moving body existing in the wide area image on the screen are detected, and the detected moving body enters the specific area of the wide area image. Control means for controlling the two-axis rotary stage so that the moving body tracks the wide-area image imaging means and the high-magnification image imaging means;
Video output means for outputting a high-magnification image of the moving body taken by the wide-area image imaging means and the high-magnification image imaging means;
A surveillance camera characterized by comprising:   7. The surveillance camera according to claim 6, wherein the specific area is a central portion of a wide area image.   8. The surveillance camera according to claim 6, wherein the moving body is a person.   9. The surveillance camera according to claim 6, further comprising storage means for recording the video output.

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